About a year later, on May 9, 1979, a pipe bomb was placed in a room at Northwestern University. A Northwestern graduate student picked up the bomb, and it exploded, injuring him.
Later that year, on November 15, a bomb exploded aboard American Airlines flight 444, en route from Chicago to Washington, D.C. Although the plane landed safely, 12 passengers were treated for smoke inhalation. Investigators later determined that the bomb was inside a mail parcel in the cargo section of the plane. They determined that the package was mailed from Elgin, Illinois.
Up to this point, the bombs were treated as separate cases. If there was any thought that these were the work of a single man, it wasn't reflected in the work of the federal and local authorities involved. It took an attack against a well-known public figure to bring the UNABOMber to the attention of federal investigators.
Postal Inspectors responded to the Wood bomb, having little or no knowledge about Flight 444. They contacted the Federal Bureau of Investigation (FBI) to investigate the Wood bombing. A case file was opened, and the case was called "UNABOM," according to the FBI's six-letter naming convention. "UNA" stood for "United Airlines." Because of design similarities between the Wood bomb and the Flight 444 bombing, they attributed the two bombs to the same actor. Eventually, they also included the two Northwestern bombings to the UNABOMber as well.
One similarity noted among several of the the four bombs was the homemade "initiator" used in each device. Another "junkyard" appearance of the devices: the soldering was clumsily-done, and all of the wood used in the devices was of low quality.
A loosely-organized joint task force was created between the FBI and the Postal Inspection Service. The investigation quickly exppanded to include Renssaeler Polytechnical Institute (the return address on the first mail bomb), Northwestern University, and United Airlines; the closest attention was focused on university students.
On October 8, 1981, a University of Utah student stumbled onto a large package outside a university computer mainframe room. Apparently, the package had been there for some time. The student moved it, then became suspicious and contacted university security. Security officials determined that the package contained a pipe bomb and a can of gasoline. It also contained another reference to "FC." Security officials took the device into a women's restroom and blew it up. They then contacted the UNABOM task force.
In May 1982, Patrick C. Fisher, a professor at Vanderbilt University in Tennessee, received a device in the mail. It had been sent to his former address at Penn State University and duly forwarded to his office at Vanderbilt. He had not worked at Penn State for two years. The return address was that of a professor at the University of Utah, and it had been mailed from Utah's Brigham Young University. Fisher's secretary opened the package and was injured when it exploded. This sink-trap device had wooden end-plugs.
On July 2, 1982, Diogenes Angelakos picked up a device in the teacher's lounge at the University of California at Berkeley, and was slightly injured when it exploded. Although the device had a handle and complicated-looking dials, these were basically for show: it was another pipe bomb inside a gasoline can. The bomb bore another "FC." The device included a note which read: "Wu, it works. I told you it would. RV." The ubiquitous "FC" was again included in the device. The note was associated with the serial bomber because it was typed on the same type of notepaper used as electrical insulators in the device.
By this point, the FBI and the Postal Inspection Service had demarcated the investigation: the FBI would handle placed devices, while the Postal Inspection Service would investigate mailed devices. Although the devices were becoming more powerful with each attack, the UNABOMber was still a craftsman, refusing to purchase readily-available components, choosing instead to manufacture them himself. Profiles of the UNABOMber were still very much at sea: investigators were putting together a profile of a serial bomber - a virtually unknown commodity - by reference to previous serial arsonists.
In May of 1985, the bomber struck again. He returned to the same building in Berkeley, this time placing a device in a computer study area. A graduate student picked up the device and it exploded, causing serious injury. This device was notable as it was the first pipe device that used metal caps, as opposed to the wooden caps (which were less destructive) used in previous devices. The ubiquitous "FC" was again included in the device; it also used the UNABOMber's twin-itiator construction.
Investigators arrived quickly to the Berkeley site. While they were there, they received word from Boeing Corporation's fabrication plant, near Seattle, Washington, that a device had been received in the mail. It had been sitting in their receiving office for nearly a month untouched until someone opened it. The device did not explode, apparently because the batteries dried up while it sat, untouched. The local bomb squad took pictures of it, then took it out back and counter-charged it, detonating it.
The database of potential suspects was now getting very large, including students and alumni of at least five universities, and employees and customers of at least three companies. Decisions had to be made to focus the investigation. At this point, still focusing on university students, the UNABOM task force decided to generally remove anyone from the database born before 1955. Very little had been released to the press up to this point about the investigation, as investigators were very cautious about discussing components of the devices or information about the investigation.
In November 1985, Professor James McConnell received a letter and parcel at his home in Ann Arbor, Michigan. It was supposedly from Ralph Kloppenburg, a Ph.D. candidate at the University of Utah specializing in the history of science. The letter stated that Kloppenburg wanted McConnell to review his thesis, contained in the enclosed parcel, with special attention to Chapters 11 and 12. McConnell's student secretary opened the parcel and was injured when it exploded. The device was mailed on November 12.
On December 11, 1985, the UNABOMber claimed his first fatality. Hugh Scrutton was behind the strip mall in Sacramento, California, where he ran a computer rental store. He apparently bent over to pick up a package in the parking lot, when the parcel exploded. He was killed. .
After this, the UNABOMber was quiet again. In February 1987, the bombing spree maimed another victim. Two witnesses saw a man walk into the parking lot behind CAAMs, Inc., another computer rental store in residential Salt Lake City, Utah. He placed a wooden device in an empty parking space, then walked away. Around 11:00am, an Gary Wright, the owner of CAAMs, drove up and spotted the device in his parking place. He stopped short, got out of his car, and kicked the device. It exploded, severing a nerve in Wright's arm.
Based on the descriptions of one of the two witnesses, a Canadian sketch artist put together the first drawing of the UNABOMber. The description was very incomplete, and was contradicted by the other witness. Nonetheless, it confirmed the UNABOM task force's belief that they were dealing with a relatively young, relatively well-off suspect.
The next year, the second UNABOM victim was killed. On December 10, 1994, Advertising executive Thomas Mosser opened a parcel he received at his North Caldwell, New Jersey, home. It exploded, and he was killed. The package had been mailed from San Francisco, California a week earlier.
Four months later, the UNABOMber claimed his final victim. Gilbert Murray, the president of the California Forestry Association, opened a parcel on April 24, 1995, sent to the Association's office, addressed to his predecessor, William Dennison. The device, mailed on April 20, exploded upon opening, and Murray was killed.
On April 3, 1996, following a lead given by his brother, federal agents raided the rural Montana home of Theodore John Kaczynski, seizing him and placing him under arrest. He was held in custody for fifteen months while questions of venue and other pretrial matters were sorted out. The trial is set to begin on Monday, December 29, 1997, in Sacramento California, before the district court for the Eastern District of California.